151 results about "Noise power" patented technology

The invention discloses a high-precision magnetic field data acquisition unit for aeromagnetic measurement and an acquisition method thereof, belongs to the technical field of aeromagnetic measurement, and solves the problems that the acquisition resolution of an aeromagnetic measurement magnetic field is low, the measurement precision is influenced by a power supply and electromagnetic interference, and the data processing and storage reliability is insufficient. According to the invention, a framework of'acquisition module + control module 'is adopted, the acquisition module realizes high-precision sampling through low-noise power supply, differential reference and analog front-end full-link conditioning, the control module completes error compensation and aeromagnetic compensation through a Zynq core, and the 1nT-level magnetic field acquisition precision is achieved by matching an anti-interference design and stable storage and transmission. The 1nT-level magnetic field acquisition precision in the aeromagnetic measurement process is achieved, the signal acquisition precision and stability are remarkably improved, electromagnetic and power interference is effectively inhibited, the reliability of data processing, storage and transmission is guaranteed, and the strict requirements of aeromagnetic measurement for precision and interference resistance are met.

The embodiment of the invention provides a short-wave full-frequency staring-distributed cooperative frequency, channel and link measurement method. The method is applied to the field of short-wave measurement, and comprises the following steps: performing multi-phase filtering on a received broadband signal to obtain a multi-channel signal; determining signal power and noise power of the multi-channel signal, and determining frequency availability according to the signal power and the noise power; selecting an available frequency according to the frequency availability, measuring through a linear frequency modulation signal transmitted in a channel to obtain a channel characteristic parameter, and determining the channel availability according to the channel characteristic parameter; signals with different waveforms are transmitted in a specified link, link characteristics are obtained through measurement, and link availability is determined according to the link characteristics; the frequency availability, the channel availability and the link availability are subjected to statistical analysis to obtain a statistical analysis result, data support is provided for multi-link cooperative transmission strategy adjustment and link access decision, and the efficiency and reliability of short-wave communication are improved.

The invention provides a water quality suspended matter detection system and method based on sensing data, and belongs to the technical field of water quality suspended matter detection. Gain compensation is performed on a mixed optical signal based on backward spontaneous radiation noise power, so that the influence of self gain drift of a sensor and environmental interference on a signal baseline is effectively eliminated; the adaptive variational mode decomposition algorithm decomposes the standardized signal into a plurality of intrinsic mode functions, accurately extracts signals strongly related to the physical characteristics of the target suspended particulate matter, generates a particulate matter characteristic waveform signal with an optimized signal-to-noise ratio through the intrinsic mode functions screened out through weighted stacking, further highlights the time-frequency characteristics of the target signal, and improves the accuracy of the particulate matter characteristic waveform signal. Each independent particulate matter signal event is accurately separated by adopting a dynamic threshold peak value detection algorithm, and the detection accuracy is improved by extracting a multi-dimensional feature vector from each signal event and distinguishing target particulate matters from interferents by utilizing a pre-trained event classifier.

The invention provides an 802.11 be multi-user system receiver signal-to-noise ratio estimation method, device and equipment and a medium, and the method does not only depend on a limited number of pilot frequency subcarriers in a frequency resource unit where a target user is located any more, but analyzes and verifies an EHT-SIG field to estimate the signal-to-noise ratio of the target user. And a plurality of frequency resource units whose cyclic redundancy check results are verified to be correct are screened out, and all pilot frequency subcarriers contained in the reliable frequency resource units are combined to be jointly used for estimation. According to the method, a plurality of cyclic redundancy check results are combined to check all reliable pilot frequency subcarriers in a correct frequency resource unit to estimate the signal-to-noise ratio, so that the sample cardinal number of noise power estimation is remarkably increased; the problem of low estimation precision caused by too few pilot frequency subcarriers of a single user due to dynamic allocation in an 802.11 be multi-user system is effectively solved, so that the overall accuracy of signal-to-noise ratio estimation is improved.

The application relates to a real-valued super-resolution direction estimation method of a high-order acoustic field sensor array, which uses a received signal covariance matrix to approximately calculate an estimated value of noise power, avoids the iterative operation process of noise power in the prior art, improves the calculation efficiency, and reduces the floating-point operation amount. By constructing an augmented matrix, the array receiving data matrix and the array manifold matrix with a multi-dimensional structure of an element are made into Hermitian matrices, so that the unitary transformation processing of the related parameters of the high-order acoustic field sensor array is realized. On the basis of obtaining the array receiving data matrix and the array manifold matrix in the real number domain, the array receiving data matrix and the array manifold matrix are applied to a sparse approximate minimum variance method with a variable exponential factor, and the completely real-valued sparse approximate minimum variance direction estimation with a variable exponential factor is realized.

The application belongs to the field of GPS positioning, and relates to a dynamic GPS signal interference influence evaluation method and system, which comprises the following steps: calculating the instantaneous position vectors and velocity vectors of visible satellites, a receiver and an interference source in the Earth-Centered Earth-Fixed coordinate system; obtaining the directional gain of a receiving antenna to multiple visible satellite signals and multiple interference signals respectively; calculating the noise power spectral density, the power of multiple visible satellite signals and the power of multiple interference signals arriving at the radio frequency front end of the receiver; modeling the equivalent carrier-to-noise ratio to obtain the equivalent carrier-to-noise ratio of multiple visible satellites; simulating the influence of the visible satellites on the code tracking loop of the receiver to obtain the pseudorange measurement error of multiple visible satellites; and performing positioning solution through a weighted matrix least square method to obtain the positioning accuracy, so that the interference effect can be accurately, real-timely and quantitatively evaluated.

Provided is an interference removal device (1) capable of inhibiting deterioration due to noise emphasis. The interference removal device comprises: a data symbol extraction unit (11) for outputting a data symbol signal (101); a null symbol extraction unit (12) for outputting a null symbol signal (102); a data symbol power calculation unit (14) for calculating a data symbol power calculation estimation value (104); a null symbol spectrum calculation unit (15) for calculating a null symbol spectrum (105); an interference center frequency estimation unit (16) for outputting an interference center frequency estimation value (106); an interference bandwidth estimation unit (17) for outputting an estimation interference bandwidth (107); and an interference removal unit (18) for generating an interference replica signal and multiplying the interference replica signal by a weight factor for each frequency in accordance with the ratio of a noise power component and an interference power component included in the interference replica signal to thereby inhibit deterioration due to noise emphasis.

The invention relates to the field of cell antenna factor calibration, in particular to a power domain estimation method and device based on GTEM cell antenna factor calibration. The scheme comprises the following steps: determining a working frequency band according to application requirements, and selecting a plurality of calibration frequency points in the working frequency band; performing reference field intensity calibration on each selected calibration frequency point; measuring an initial azimuth angle based on the GTEM cell; measuring noise power, and establishing a noise power matrix; measuring the receiving power under the full angle; subtracting the corresponding noise power from the measured receiving power to obtain net signal power; calculating an antenna factor of the antenna under the current set angle and the calibration frequency point according to the antenna factor definition; and finally, calibrating and verifying the antenna factors. The method is suitable for power domain estimation based on GTEM cell antenna factor calibration.

Disclosed herein is an apparatus of a communication device, the apparatus includes a processor configured to estimate noise power characteristics within a frequency band based on a received signal comprising a plurality of subcarriers within the frequency band, wherein the noise power characteristics comprises a plurality of noise samples. The processor is also configured to estimate a noise covariance matrix by averaging a number of noise samples of the plurality of noise samples. The processor is also configured to apply a whitening that is based on the noise covariance matrix to subsequent received signals.

A method for measuring a sensitivity of a receiver is provided. The method includes: during a first stage, controlling a signal generator to transmit an input test signal to an input node of the receiver, wherein the receiver generates an output test signal on a first output node of the receiver according to the input test signal; calculating a path loss from the input node of the receiver to the first output node of the receiver according to the input test signal and the output test signal; during a second stage, measuring an output noise power on a second output node of the receiver after a load is connected to the input node of the receiver; and calculating the sensitivity of the receiver according to the path loss and the output noise power. The load may be an antenna or a 50-ohm impedance load.

The invention discloses a self-adaptive carrier frequency point and bandwidth filtering noise reducer and a method thereof. The method comprises the following steps of: dividing the whole receiving bandwidth of a receiver into N segmented frequency spectrums; calculating N noise power thresholds corresponding to the N segmented spectrums, and setting cascaded N noise elimination modules according to the N segmented spectrums and the N noise power thresholds; the method comprises the following steps: inputting carrier data into cascaded N noise elimination modules, filtering an ith segment frequency spectrum through an ith noise elimination module to obtain ith segment frequency spectrum filtering data, calculating the average power of the ith segment frequency spectrum filtering data, comparing the average power with an ith preset noise power threshold value, if noise is judged, subtracting the noise from the original carrier data, and if the noise is not judged, subtracting the original carrier data from the ith preset noise power threshold value; and if the ith section of spectrum data contains signal data, reserving the signal data, and directly outputting the input signal of the ith noise elimination module as the input signal of the (i + 1) th noise elimination module. According to the method, the noise can be effectively reduced in a self-adaptive manner under the condition that the carrier frequency point and the bandwidth are unknown.

This application discloses a method and product for self-diagnosing external interference. The method includes: acquiring the inherent parameters of the frequency-using terminal to calculate the theoretical noise floor; measuring the total received power in real time and calculating the super-noise power accordingly; when the super-noise power exceeds a preset power threshold, acquiring the baseband demodulation quality parameters of the current channel; and performing correlation discrimination based on the super-noise power and baseband demodulation quality parameters. When the super-noise power is high and the demodulation quality is below a preset threshold, it is determined to be external interference; otherwise, it is determined to be a strong useful signal. This application establishes a two-dimensional causal correlation model between physical layer power and baseband layer quality within the terminal, enabling real-time and objective self-diagnosis of external interference from the terminal's own perspective, thus improving the objectivity, timeliness, and accuracy of the diagnosis.

The invention discloses an efficient soft demodulation method and system suitable for pulse position modulation, and relates to the technical field of laser communication. Pulse position modulation signals and preset channel parameters are received, and time slot receiving signals are acquired based on the pulse position modulation signals, the preset channel parameters comprise the optical signal intensity and noise power of a Gaussian channel, the pulse optical signal electron number of a Poisson channel and the electron number of an ambient optical signal; inputting the time slot receiving signal and a preset channel parameter into a pre-established soft demodulation model based on a maximum posteriori and a maximum likelihood criterion, and outputting to obtain a log likelihood ratio LLR of a modulation bit; meanwhile, the index logarithm operation of the LLR is simplified by adopting a max-log method, and the calculation complexity is reduced; aI is adopted to optimize the scaling coefficient for the performance loss caused by soft demodulation calculation simplification to balance the performance loss and the implementation complexity, so that the transmission efficiency of PPM modulation is improved.

The invention relates to a satellite navigation array anti-interference method and device based on adaptive diagonal loading. The method comprises the following steps: acquiring sampling quantized data of an array antenna element, estimating noise power and initializing a loading value, periodically updating a loading coefficient to obtain a real-time loading value, constructing a diagonal loading correlation matrix and solving a weighting value, outputting an anti-interference signal, constructing a feedback factor based on a visible satellite precision factor and a carrier-to-noise ratio, and outputting the anti-interference signal. And a counter is adjusted by comparing feedback factors, the updating direction of the loading coefficient is switched when a threshold value is reached, and closed-loop self-adaptive optimization of the loading value is realized. The method does not need prior information, adapts to various navigation systems and power modes, is excellent in anti-interference performance and low in implementation cost, and effectively solves the problem of performance deterioration of a traditional method.

The application discloses a kind of based on mixed intelligent reflecting surface auxiliary's integrated sensing method, it is related to wireless communication technical field, including: establishing integrated sensing system, the system includes a dual-function base station, a mixed intelligent reflecting surface, K communication users and L perception targets;Communication model and perception model are constructed, according to the communication model and perception model, establish the optimization problem of maximum L perception targets in minimum perception beam gain under the constraint of maximum total transmit power of dual-function base station, communication quality constraint of communication user, maximum total transmit power constraint of mixed intelligent reflecting surface and noise power constraint;The optimization problem is transformed and solved based on alternating variable iterative optimization algorithm, and the final optimal solution of optimization problem is obtained.The application can maximize the minimum perception beam gain of perception target, and improve the sensing ability of system.

The application provides a frequency switching-based continuous variable quantum key distribution anti-noise method and system, which comprises the following steps: a frequency switching step: acquiring a channel state, calculating a channel noise power spectrum, and finding a position with the lowest channel noise power, which is recorded as a window; and moving a transmission signal spectrum of a sending end to the window for transmission; an optimal filtering step: moving a received signal spectrum of a receiving end back to a baseband, and then filtering the received signal by using a low-pass filter to retain the transmission signal. The application combines the frequency switching idea with the filter, avoids the transmission signal from being submerged by the channel noise, is beneficial to reducing the noise components received by the receiving end of the continuous variable quantum key distribution system as much as possible, can effectively reduce the excessive noise in the system, and improves the system key rate.

The invention particularly relates to a parameter adaptive hybrid disturbance serial cancellation (SC) decoding method for polarization codes. Aiming at the problems of disturbance parameter fixation and rigidity, lack of channel adaptability and dependence on off-line parameter search in the existing hybrid disturbance serial cancellation (HPSC) decoding method, the method comprises the following steps: firstly, establishing a linear mapping relation between disturbance noise power and channel noise power to realize automatic adaptation of a channel environment; then, the check characteristic of a cyclic redundancy check code is used as a detection indicator of a local optimal trap, intelligent switching is carried out between adaptive random disturbance and adaptive biased disturbance, and a bias adjustment strategy dynamically changing along with the number of iterations and the reliability of a received symbol is introduced in the biased disturbance stage; therefore, parameter-adjustment-free high-performance decoding is realized on the premise of keeping low complexity of SC. Simulation results show that compared with a traditional HPSC decoding method with fixed parameters, the method provided by the invention has better block error rate performance, and has lower average decoding iterations in a high signal-to-noise ratio region.

The application discloses a self-interference suppression method based on wideband digital beam forming, which comprises the following steps: S1. After a transmitter performs digital-to-analog conversion on a desired transmission signal through transmission beam forming, the signal is processed through a radio frequency transmitting device and then transmitted to a transmitting antenna array for transmission; S2. A receiver receives the signal from the transmitting end through the receiving antenna array, processes the signal through a radio frequency receiving device, performs analog-to-digital conversion, completes receiving beam forming, and gives a residual interference representation of the receiver; and S3. Coefficients of the transmitting beam forming and the receiving beam forming are designed, the self-interference coupled to the receiving array is suppressed while ensuring normal transmission of the transmitting array and normal reception of the receiving array, and the desired signal is normally demodulated. The application utilizes the symmetry characteristics of the coupled self-interference channel, alternately iteratively optimizes the transmitting and receiving beam forming coefficients, and minimizes the residual interference and noise power coupled to the receiver.

The application discloses an uplink multi-user random modulation and OAMP detection method, which comprises the following steps: independently modulating and transmitting signals of each user, and receiving the sum of signals of each user; performing linear estimation according to prior distribution of the transmitted signals of each user, state information of a channel matrix, estimation error of the channel matrix and channel noise power; performing nonlinear estimation according to the prior distribution of the transmitted signals of each user and the estimation and variance obtained by linear estimation, so as to obtain the nonlinear estimation and variance in the present iteration; continuously iterating the linear estimation and the nonlinear estimation, and performing hard decision according to the linear estimation and variance obtained by the last iteration to obtain a final decoding result. The application independently modulates all users, considers the channel estimation error, does not require that the entire equivalent channel matrix has right unitary invariant characteristics, reduces performance loss, and obtains detection performance which is obviously superior to that of the prior OAMP.

A channel tracking control method, applied to a multiple-input multiple-output orthogonal frequency-division multiplexing communication system, includes the following operations: during a preamble period of a packet, determining a noise power according to a preamble of the packet, in which the preamble is transmitted via sub-carriers; during the preamble period, determining a clipping level value corresponding to a sub-carrier in the sub-carriers according to a noise reduction factor of a channel detection circuit; during the preamble period, determining a signal-to-noise ratio of the sub-carrier according to the clipping level value and the noise power; and according to the signal-to-noise ratio and a target signal-to-noise ratio, controlling a channel tracking circuit to stop tracking a channel response of the sub-carrier during a payload period of the packet.

The embodiment of the invention relates to the technical field of base stations, and discloses a radio frequency chip structure, a radio frequency module and communication equipment, and the radio frequency chip structure comprises a substrate, and a power amplifier PA, a first low-noise power amplifier LNA and a second LNA which are packaged on the substrate; the substrate is provided with a first input pin, a first output pin, a second input pin, a second output pin, a third input pin and a third output pin; the input end of the PA is connected with the first input pin, and the output end of the PA is connected with the first output pin; the input end of the first LNA is connected with the second input pin, and the output end of the first LNA is connected with the second output pin; the input end of the second LNA is connected with the third input pin, and the output end of the second LNA is connected with the third output pin. According to the embodiment of the invention, a plurality of radio frequency devices are packaged through one chip structure, the chip manufacturing cost is reduced, and the assembly efficiency and flexibility are also improved.

The embodiment of the invention discloses a voice quality detection method, and the method comprises the steps: determining a voice classification result of each frame through a preset voice activity detection algorithm, dividing audio data into a voice segment and a non-voice segment, taking each frame of audio of which the classification result is the voice data in the non-voice segment as an interference frame, and carrying out the elimination. And calculating a signal-to-noise ratio of the voice segment to determine a quality detection result. And the interference frame which is misjudged as voice is eliminated from the non-voice segment, and purer noise estimation is obtained. Based on the calculated signal-to-noise ratio, the voice signal quality can be reflected more truly, and the problems of noise power overestimation and signal-to-noise ratio underestimation caused by VAD false detection are effectively solved, so that the accuracy and reliability of voice quality detection are improved.

The application provides a self-adaptive signal beam forming method, device, equipment and storage medium. The method is based on a 2N+1 element uniform linear array receiving signal. The method comprises the following steps: a multiple Toeplitz matrix is constructed, and a covariance matrix is obtained by merging; a signal direction vector is calculated according to an eigenvalue and an eigenvector, and an expected signal direction vector is obtained by optimization; a noise power is estimated by using a minimum eigenvalue, a corresponding relationship between a signal power and the eigenvector is established, and an expected signal power is determined; a covariance matrix of mutually independent noise is reconstructed according to the noise power, the corresponding relationship and the expected signal power; and the expected signal direction vector and the reconstructed covariance matrix are brought into a Cap on beam former, and an optimal weight vector is calculated to control beam forming. The method improves the performance and reliability of the beam forming system in a complex signal environment by constructing a multiple Toeplitz matrix and using the characteristics of the multiple Toeplitz matrix for signal decorrelation and covariance matrix reconstruction.

A relay station includes a plurality of antennas and a controller. In non-regenerative relay of a first signal, the controller estimates an SINR of the first signal at a reception station after the relay on the basis of a transmit power of the first signal at a transmission station, first propagation characteristics between one or more first antennas set as reception antennas for the first signal and the transmission station, second propagation characteristics between one or more second antennas set as transmission antennas for the first signal after the relay and the reception station, a noise power and an interference power at the relay station, and a noise power at the reception station, and determines the first antennas and the second antennas in a combination that makes the SINR of the first signal at the reception station maximum respectively as the reception antennas and the transmission antennas.

The application belongs to the technical field of underwater acoustic array signal processing, and discloses a covariance fitting azimuth estimation method under non-Euclidean metric based on matrix reconstruction, which constructs a noise standard deviation matrix, judges the noise type, extracts the heteroscedastic characteristic from the noise standard deviation matrix, uses the extracted noise power to whiten the array received signal, calculates a sample covariance matrix SCM, reconstructs a model covariance matrix MCM matched with the whitening processing, uses the symmetric Kullback-Leibler divergence as the non-Euclidean metric to calculate the difference between the SCM and the MCM, and realizes the DOA estimation by traversing the azimuth grid points and minimizing the symmetric Kullback-Leibler divergence. The application uses the symmetric SKL divergence to solve the matrix-matrix comparison problem, and focuses on the low SNR condition. The more complete modeling of the noise interference parameter can reduce the DOA estimation failure threshold by about 20 dB.

The application discloses a channel estimation method and related device, wherein the method comprises: performing minimum mean square error (MMSE) channel estimation based on the product of the first amplitude factor and the first noise power of the first dimension, the first channel autocorrelation matrix of the first dimension, and the first diagonal matrix to obtain the channel estimation value matrix of the first dimension; wherein the channel estimation value matrix of the first dimension is obtained by performing MMSE channel estimation in the non-last step of the multi-dimensional step-by-step MMSE channel estimation; the first amplitude factor is a positive number less than or equal to 1; and performing MMSE channel estimation based on the channel estimation value matrix of the first dimension, the second channel autocorrelation matrix of the last dimension, the second noise power and the second diagonal matrix to obtain the multi-dimensional channel estimation value matrix. The method can improve the performance of the multi-dimensional step-by-step MMSE channel estimation.

This invention belongs to the field of noise floor reduction and proposes a frequency-band noise floor reduction method based on a spectrum analyzer. This invention can solve the problems of uneven noise power distribution and excessive noise power estimation. It includes the following steps: acquiring the noise floor signal of the spectrum analyzer, wherein the noise floor signal is a low-pass or band-limited white noise signal with a specified bandwidth; dividing the specified bandwidth into a first number of sub-segments and dividing the signal power before denoising into a first number of sub-segments; estimating the noise power under the specified bandwidth and dividing it into a first number of sub-segments; denoising each sub-segment and calculating the noise power spectral density of each sub-segment after denoising based on the bandwidth after segmentation, the signal power before denoising after segmentation, and the estimated noise power after segmentation; and ensuring that the noise power spectral density after denoising is not negative by using the compression factor method or the square root method.

The application provides a CQI acquisition method, a receiving device and an optical communication system. The method comprises the following steps: receiving a plurality of reference signals transmitted through a channel of optical communication, wherein the transmission power of each reference signal is different; acquiring a channel gain; measuring a plurality of noise powers corresponding to each reference signal according to the received plurality of reference signals; calculating a first noise coefficient related to non-independent noise according to the transmission power of the reference signal, the channel gain and the measured noise power; and acquiring the CQI corresponding to each reference signal by using the corresponding relationship between the first noise coefficient and the CQI stored in advance, and averaging to obtain an average CQI as the CQI of the channel.

The invention provides a radar signal processing method and device, terminal equipment and a storage medium, and the method comprises the steps: obtaining an amplitude vector and a phase vector of each received signal, and generating an angular frequency estimation value and an initial phase estimation value based on maximum likelihood estimation; calculating the GLRT statistical magnitude of the received signals according to the prior knowledge condition of the signal amplitude and the noise power, comparing the GLRT statistical magnitude with a preset threshold value, and generating a target detection result of each received signal; wherein the GLRT statistic is the ratio of the likelihood when the alternative hypothesis is established to the likelihood when the zero hypothesis is established; receiving signals with targets are extracted according to the target detection result, an effective detection signal index sequence is established, and the target distance and the target relative speed are generated according to the angular frequency estimation value and the initial phase estimation value of each receiving signal in the effective detection signal index sequence. According to the invention, the robustness and reliability of the radar system can be improved without improving the hardware level.